Pests in plants - Identification and Procedure

Asked October 2, 2018, 9:34 AM EDT

I have a large variety of houseplants. I recently found small clouds of black flying insects around one pothos plant, then a basil. Thinking these were fungus gnats, which I have dealt with in the past, I quarantined the affected plants to prepare for soil replacement and treatment when I saw white spider-like bugs crawling in the soil. These are certainly not fungus gnat larvae, which are fast and worm-like. I have attached two photos, one I managed to catch of one of the flyers, the crawlers have not held still long enough to capture, but I have attached a stock photo of a fed tick - I know that is not what this is, but is the closest comparison I can find. They are very small and have large, swollen abdomens that are white or brownish and somewhat translucent-looking, with the legs clustered to the front. The smallest ones are simply white moving specks. Soil drenches with neem and a hydrogen peroxide solution have so far failed to kill the crawlers in the soil. Plants most highly affected have begun to look anemic, so they would seem to be doing some damage. I would very much appreciate any advise on what these pests are and how to deal with them. Thank you! UPDATE: I have also now seen fungus gnat larvae in the soil, so the flyers and crawlers may be unrelated, and the tick-like white crawlers are not necessarily a species with an aerial form.



District of Columbia County District of Columbia houseplants fungus gnats

1 Response

The left photo shows an adult fungus gnat. We recommend that you take the affected plants outdoors and repot with fresh potting soil. Monitor the plants and do not overwater. See our website on fungus gnats http://extension.umd.edu/hgic/plants/fungus-gnats-houseplants

mh